A dust storm is a moving wall of dust and debris that usually arrives suddenly. Dust storms form in arid regions such as the U.S. Southwest when dust particles and fine-grained soils are blown into the air, often lifted by strong winds. Dust storms can be up to 100 miles wide and several thousand feet high. They travel an average of 25 to 50 miles.

Dust storms are common in the Southwest during the region’s summer monsoon season, when winds shift, temperatures rise, and conditions are extremely dry. Powered by intense ground heating, thunderstorms can produce strong downdrafts. These downdrafts blow up loose sand on the desert floor, creating a dust storm.

Dust storms can contain particulate matter, which can be a serious threat to human health if it accumulates in the respiratory system. Dust particles can lead to respiratory problems, particularly for people with asthma. They can harm sensitive lung tissue, irritate the lungs, and trigger allergic reactions, including asthma attacks. Exposure to dust in dust storms can cause coughing, wheezing, and runny noses. Breathing a lot of dust over a long period of time may cause chronic breathing and lung problems.

Dust storms may expose people to fungal spores that can cause a disease known as Valley Fever, or coccidioidomycosis. These spores live in the desert soil of semi-arid areas and are native to the Southwest. They may become airborne and spread during a dust storm.

Valley Fever is often mild, with no symptoms. Some people may experience flu-like symptoms, such as fever, coughing, and muscle aches. A small number of people may develop a chronic infection or pneumonia from Valley Fever. Native Americans, Hispanics, and African-Americans are more likely to develop an infection from Valley Fever.

Dust storms can have a significant effect on agriculture by damaging crops and harming livestock. They can blow away valuable topsoil, cause erosion, and reduce the land’s nutrients and water-holding capacity.

Dust storms reduce visibility, at times to zero. They can make driving hazardous, cause accidents, and force airports to close because of poor visibility and dust conditions. Dust storms can take down power lines, cause power failures, damage infrastructure, and harm computers and communications equipment from the buildup of dust.

Some intense dust storms are called haboobs, from the Arabic word for “wind.” They are most frequent in the Southwest from May through September. They have winds of higher than 30 miles per hour, may raise dust to higher than 3,000 feet, and last for an average of less than three hours.

Dust storms can affect areas for days and even up to months.

Drier conditions projected to result from climate change in the Southwest will likely lead to increased dust storms, according to the U.S. Geological Survey.

This description is based on the information found in the Web links listed with this topic.